Touch panel and manufacturing method thereof

ABSTRACT

A touch panel is formed by firstly forming a film layer on a first plate, and next, sequentially forming a buffer layer on the film layer, forming a sensing layer on the buffer layer, forming a second plate on the sensing layer. After the foregoing formation procedures, the first plate is removed from the film layer. Next, a cover is attached to the film layer. In this way, the film layer is located between the cover and the buffer layer. Finally, the second plate is removed from the sensing layer, so as to form a touch panel with the features of light weight, thin thickness and low costs.

The current application is a Continuation application of U.S.application Ser. No. 14/467,992, filed on Aug. 25, 2014, which claims aforeign priority to the Chinese Patent Application 201310454870.1, filedon Sep. 29, 2013, and the Chinese Patent Application 201410244190.1,filed on Jun. 4, 2014. The entire contents of the above-referencedapplications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to touch panel technology. Inparticular, it relates to a touch panel with a buffer layer and themanufacturing method thereof.

BACKGROUND OF THE INVENTION

In today's consumer electronics market, touch panel has been applied toa wide variety of different electronic products, such as smart phones,normal mobile phones, tablet PCs, notebook computers and etc. Inaddition, the market increasingly demands new types of touch panel thatis stronger, thinner, lighter, and less expensive.

Touch panel is currently one of the most popular technology that hasbeen used various devices as mentioned above. One major reason countsfor its popularity is that touch panel is able to provide a moreintimate and intuitive experience for a user, which has eliminated therequirements for the physical facilities, such as mouse or key board, inbetween the working device and the user. As the user can directlyperform operations or make instructions via the objects displayed on thescreen, the touch panel is able to provide the user with a humanizedoperation interface between the users and the electric products.

However, with the increasingly higher demand for the touch panel that iswith a thinner and lighter structure and a lower production cost, thestructures and manufacturing processes of the current touch panels needto be further improved. Therefore, one objective of the presentinvention is to provide a touch panel that is manufactured through a newmethod, which allows it to be not only thinner, but also with desirableappearance and low costs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-8 are the illustrations of the procedure steps of themanufacturing process of one embodiment of the present invention.

FIGS. 9 and 10 are the illustrations of the manufacturing process ofanother embodiment of the present invention.

FIG. 11 is the illustrations of the manufacturing process of anotherembodiment of the present invention.

FIGS. 12A. 12B, 13 and 14 are the illustrations of the manufacturingprocess of yet another embodiment of the present invention.

FIG. 15 is a structural view of the touching panel sensing layer of oneembodiment of the present invention.

DETAIL DESCRIPTIONS OF THE INVENTION

All illustrations of the drawings and exemplary embodiments are for thepropose of describing selected versions of the present invention, andare not intended to limit the scope of the present invention. Moreover,in order to show the various elements clearly in the respective figures.their illustrations are only for the purpose of demonstration orindication, and thus are not drawn to scale.

The present invention has provided a touch panel and its manufacturingmethod. It has met the needs for a touch panel that is with a thinnerand lighter structure and a lower production cost.

A manufacturing method of touch panel comprises the steps set forthbelow: S1 forming a film layer on a first plate; S2: forming a bufferlayer on said film layer; S3 forming a sensing layer on said bufferlayer: S4: forming a second plate on said sensing layer; S5, removingsaid first plate from said film layer; S6: attaching a cover on saidfilm layer by a binding layer, and said binding layer being between saidcover and said film layer: and S7: removing said second plate.

In addition, the present invention has also provided a touch panelproduced via the foregoing manufacturing method. It comprises, in order,a cover, a binding layer, a film layer, a buffer layer, and a sensinglayer, said film layer being on top of said cover, said buffer layerbeing on top of said film layer, said sensing layer being on top of saidbuffer layer, and said binding layer being in between said cover andsaid film layer.

As mentioned above, the present invention has provided a touch panel andthe manufacturing method thereof. Two plates, namely the first plate andthe second plate, have been introduced into the manufacturing process ofthe present invention. Albeit they are not a part of the final product,they actually provide critical functions to the formation of the touchpanel disclosed in the present invention. With the supporting effectfrom the first plate, a sensing layer is formed on top of the filmlayer, and then the first plate is removed. And later on with thetransferring effect of the second plate, the film layer, along with thesensing layer attaching to it, is attached to the cover. In this way,the formed touch panel is with a thinner and lighter structure and alower production cost.

Besides, in regard to the plate that has been providing criticalsupporting effect to the respective layers during the manufacturingprocess of the touch panel, an adhesion promoter has been introducedbetween the plate (which is usually a glass plate) and the film layer.With its specific characteristic, such an adhesion promoter helps tomaintain the tight attachment between the film layer (which could bemade of certain organic materials, such as polyimide (PI)) and the plate(usually a glass plate), since the adhesion effect between these twotypes of materials is quite weak. Later on, prior to the removingprocedure of the first plate, the adhesion promoter, due to its uniqueproperty, can be stripped of its adhesive ability, which result to avery weak attachment between the first plate and the film layer. In thisway, it helps to separate (peel off) the first plate from the film layer(and other layer formed on the film layer), which it previously helpedto bond together.

Moreover, the sensing layer is located on one side of the film layer,whose the other side is attached to the cover. In this way, during thefuture process of attaching a flexible circuit board to the sensinglayer, it helps to prevent the foregoing process from affecting theflatness of the attachment between the film layer and the cover.

Further, a buffer layer has been introduced between the film layer andthe sensing layer. This buffer layer, with its particular properties,helps to buffer the striking differences on many crucial propertiesbetween the film layer and the sensing layer, for example, theirdifferences on the index of refraction and the coefficient of thermalexpansion (CTE). With the existence of such a buffer layer between thefilm layer and the sensing layer, the negative effects from theformation of the sensing layer to the film layer, as well as the stressderived from the removal of the first plate to the sensing layer, havebeen significantly reduced.

Furthermore, since the film layer, in the present invention, has beenmade of certain unique organic materials (such as PI), it can be made ofa very thin layer (can be as thin as a couple of microns) and meanwhile,retains its advantageous characteristics, for example, the desiredstrength, toughness and thermostability. This technical feature greatlyhelps to reduce the thickness of the touch panel of the presentinvention.

In reference to the accompanying drawings and exemplary embodiments, thepresent invention will be further described below in more details. It isnoted that concerning the description that one component is located ontop of or below another component, it comprises the embodiments thattheses two components are in contact with each other, and theembodiments that a third component is located in between these twocomponents. Further, in order to make the illustrations more helpful tounderstand the critical novel features of various embodiments of thepresent invention, the components in the figures are not drawn to scale.

In reference to FIGS. 1-8, the production process of one embodiment ofthe touch panel manufacturing method of the present invention has beendescribed sequentially. As shown in FIG. 1, a first plate 100 is firstlyprovided; next a film layer 121 is formed on top of the first plate 100.In this case the first plate 100 functions as a mechanical supporter forthe structure formed in the following steps. It can be a transparent oropaque plate, such as a piece of glass plate. Due to the fact that thisfirst plate is not a constitute component of the final touch panelproduct, it can be used with a relatively low cost material, as long assuch material is able to provide the necessary mechanical supportingfunction. For instance, instead of using the chemically strengthenedglass, the first plate can be just a simple raw glass, which helps toreduce the manufacturing costs of the touch panel disclosed in thepresent application. In addition, as would be described later, afterlater removed from the formed touch panel, the first plate can be nextrecycled as the first plate in the formation of a new touch panel, whichhas further lower the production costs. Further, it is noted that thefirst plate in the present invention is not limited to glass, it can beany other suitable material that is able to provide a proper mechanicalsupport.

Concerning the film layer 121, it could be in a single layer or multiplelayer structure, or a stacking structure that comprises a lower layerformed by a material with releasing capability and an upper layer formedby another material without releasing capability. The releasingcapability hereinafter refers to the removal of the first plate (or thesecond plate) from the layer (such as the film layer) that it ispreviously attached to. Instead of the conventional glass material, thefilm layer of the present invention can be made of a variety of suitableorganic materials, such as the previously mentioned polyimide (PI).

The materials that can be used to form the film layer 121 include, butare not limited to, polyimide (PI), polypropylene (PP), polystyrene(PS), acrylonitrile-butadiene-styrene (ABS), polyethylene terephthalate(PET), polyvinyl chloride (PVC), polycarbonate (PC), polyethylene (PE),polymethyl methacrylate (PMMA), polytetrafluoro ethylene (PTFE), cyclicolefin copolymer (COP) or any combination of the foregoing.

In addition, the film layer can be formed by coating or any othersuitable method. In one embodiment, the film layer is formed by coatingprocess. For example, a solution including material disclosed above isapplied to the first plate and then cured to form the film layer. In oneembodiment of the present invention, the first plate 100 is disposed ona movable stage, and the solution including above material with specificproportion is applied to the first plate 100 by slit nozzle, dipper orother applying tool and then spread evenly by using a coating knife,rotating the stage other tool. The solution is heated or baked tovolatilize solvent and/or polymerize precursors and/or monomers, andthen a film layer is formed. In addition, the thickness of the filmlayer could be controlled by adjusting the speed of moving the stage andspeed of applying the solution, which may be achieved by adjusting thepressure of the chamber and modifying the viscosity of solution. Theprocess of heating and baking, may include several heating steps withdifferent temperature, such as one pre-heating step with lowertemperature and one heating step with high temperature, or one gradientheating step. In one embodiment, the film layer is made of polyimide,and the solution may include soluble polyimide (SPY) and organic solventor polyamide acid (PAA) and organic solvent. The polyamide acid is theprecursor of the polyimde. The organic solvent includesdimethylacetamide (DMAC), N-Methyl-2-Pyrrolidone (NMP), 2-Buthoxyethanol(BC), γ-butyrolactone (GBL), and etc. The formation process of the filmlayer 121 is not limited on this issue. The film layer may be formed bychemical vapor deposition (CVD), spray method or other suitable method.In other embodiment, the film layer is formed by direct pressing thefilm layer on the first plate 100.

The film layer 121 can be made of polyimide (PI) with chemicalmodifications on its chain length and/or functional groups, and/orphysical modification on its surface microstructure, so that it does nothave a significant hydrophilic property, which may compromise itsfunction or appearance. In general, the longer its chain length is, thestronger its hydrophilic ability is. In such a composition, variouslength of PI chain would render the PI polymer different viscosities,which can be adjusted according to the specific requirement. The PIpolymer may be further modified by groups that do not have a significanthydrophilic property, such as groups containing halogen. The film layer121 made of fluorine containing polyimide comprising a few advantages.The light with a short wavelength cannot travel through the film layer.Accordingly, light (10 nm-400 nm) will be absorbed, rather than passthrough to reach the critical sensing layer. In this way, the film layerhas further provided an effect to protect the sensing layer from theharmful UV light. In addition, it has a high transparency and a lowwater absorbance. The latter ensures that during the procedure of wetetching the sensing layer, the film layer does not swell, which helps toproduce a touch panel product with better appearance. Moreover, duringan aging test, it does not absorb water; which would be beneficial toextend the service lives of touch panel components.

In addition, the thickness of the film layer disclosed in the presentinvention is significantly thinner than the film layers made byconventional materials. In one embodiment of the present invention, thethickness of the film layer is usually within the range from about 0.1μm to 15 μm and preferably within the range of 2 μm to 5 μm. It is alsonoted that the foregoing is not a limiting range of the film layer ofthe present invention. The film layer 121 is usually thinner than thenormal glass plate or conventional film substrate; and the film layer121 within such thickness range comprises desired mechanical properties,including strength, toughness and thermostability, as well as desiredoptical properties, such as transmittance rate. Therefore, in thepresent invention, through the adoption of a thinner film layer, it hassignificantly reduced the thickness and weight of the touch panel, andmeanwhile, it still retains excellent, optical properties and a desiredproduct appearance.

In this embodiment, the film layer 121 can be adhered to the first plate100 through a first adhering layer 110. As already mentioned, theadhesion force between the first plate (glass) and the film layer(organic polymer) is so weak that they cannot attach to each othertightly by themselves. Therefore, in order to improve the attachmentbetween the first plate and the film layer, a particular adhering layer(adhesion promoter) has been provided between them.

The first adhering layer 110 is an adhesive comprising both pro-organicfunctional groups and pro-inorganic functional groups. Morespecifically, when the first plate 100 adopts glass or other inorganicmaterials and the film layer 121 adopts polyimide (PI) or other organicmaterials, the first adhering layer 110 would comprise differentfunctional groups, which allow it to hold the first plate 100(inorganic) and the film layer 121 (organic) on its two sides,respectively. In this way, it is capable of tightly fixing the filmlayer 121 onto the first plate 100. In one embodiment, the firstadhering layer 110 is formed by coating a liquid adhesive, on the firstplate 110 and then heating/baking the liquid adhesive until the firstadhering layer 110 is formed. During the step of baking, the compositionin the liquid adhesive can cross-link the first plate, which results inbetter adherence. Afterwards, when a subsequent baking process isperformed during the step of forming the film layer, the first adheringlayer can also cross-link the film layer 121, which facilitates a betteradherence of film layer 121 on the first plate 100.

The first adhering layer 110 can be a continuous sheet-like layerbetween the first plate and the film layer. Alternatively, the adheringlayer 110 can be in a frame like shape, which is located only on theperiphery of the first plate 100. Accordingly, in the periphery region,the adhering layer 110 works to hold the first plate 100 and the filmlayer 121 together tightly: in addition, in the central regionsurrounded by the periphery, since no adhering layer present, the firstplate 100 (glass or other inorganic, material) and the film layer 121(PI or other organic material) are only loosely attached to each other.In such a fashion, it can not only ensure secure connections betweenvarious layers, but also make the future procedure of peeling off (firstplate 100) become much easier. As shown in FIG. 5A and FIG. 5B, which isan exploded view of FIG. 5A, the first adhering layer 110 is located inthe peripheral area N of the first plate 100. In this way, the bondingbetween the film layer 121 and the first plate 100 via the firstadhering layer 110 at the peripheral area N is relatively strong;whereas in the areas other than the peripheral area N (such as thecentral area M), where no first adhering layer 110 exists, the bondingbetween the film layer 121 and the plate 100 is relatively low.Accordingly, during the production process the film layer 121 not onlycan adhere to the first plate 100 tightly through the first adheringlayer 110 to ensure security, but also, during the process of peelingoff, it can be easily removed from the first plate 100 after the firstadhering layer 110 is removed. The particular removing method will bedescribed in details later.

As mentioned previously, in other embodiments, it is also possible thatthe first adhering layer 110 is made to cover the entire area of thefirst plate 100. And the film layer 121 is formed on top of the firstadhering layer 110. In particular, with such design, the first adheringlayer 110 could be made by a material with variable adhering property.More specifically, during the process of formation, the first adheringlayer 110 has a relatively strong adhering ability to the first plate100. Later on, prior to the procedure of removing the first plate 100,via the approach of soaking the first adhering layer 110 in a specificsolution or temperature treatment, its adhering ability will besignificantly reduced, which helps to peel the first plate 100 off fromthe film layer 121.

Next, as shown in FIG. 2, a buffer layer 122 is formed on top of thefilm layer 121. The buffer layer can be made of a transparent insulatingmaterial. In one embodiment of the present invention, the buffer layer122 is made of silicon dioxide (silica), and is formed by the approachof chemical vapor deposition (CVD), printing, lithography or othersuitable methods. In another embodiment of the present invention, thebuffer layer can be made of material which has refractive index matchedwith that of the sensing layer. For example, the buffer layer may bemade of titanium oxide (including, but not limited to TiO₂, siliconoxide (including, but not, limited to SiO₂, zirconium oxide (including,but not limited to ZrO₂), tantalum oxide, tungsten oxide, yttrium oxide,cerium oxide, antimony trioxide, niobium oxide, boron oxide, ceriumfluoride, magnesium fluoride, calcium fluoride or a combination thereof.In yet another embodiment of the present invention, the buffer layer 122may comprise an inorganic material and an organic material. Theinorganic material can be selected from titanium oxide (including, butnot limited to TiO₂), silicon oxide (including, but not limited toSiO₂), zirconium oxide (including, but not limited to ZrO₂),), tantalumoxide, tungsten oxide, yttrium oxide, cerium oxide, antimony trioxide,niobium oxide, boron oxide, Ti_(x)Nb_(y)O, aluminum oxide, zinc oxide,indium oxide, aluminum fluoride, platinum fluoride, cerium fluoride,magnesium fluoride, calcium fluoride, aluminum oxyfluoride and magnesiumoxyfluoride, and combination of the foregoing. The organic material canbe polymer or resin; more specifically, such as acrylic resin, polymer,polyimide (PI), polypropylene (PP), polystyrene (PS),acrylonitrile-butadiene-styrene (ABS), polyethylene terephthalate (PET),polyvinyl chloride (PVC), polycarbonate (PC), polyethylene (PE), polymethacrylate (PMMA), polytetrafluoro ethylene (PTFE), cyclic olefincopolymer (COP), polyester, phenoxy resin, silicone rubber, epoxy,poly(acrylamide) (PAM) poly(vinyl alcohol) (PVAL), poly(acrylic acid)(PAA), poly(ethyleneimine) (PEI), per fluoroalkoxy polymer resin (PFA),perfluorosulfonic acid, phenolics (PF), phenoxy, phenylene ether/oxide,poly paraphenylene terephthalamide, poly(N-vinyl pyrrolidone),poly(propylene fumarate), cellophanepoly(vinylidenefluoride-trifluoroethylene), polyallyl phthalate, polyamide (PA),polyanhydrides, polyamide-imide, polyarylate, polyarletherpolyarylsulfone, polybenzimidazolepolybutylene (PB), polybutyleneterephthalate (PBT), polybutylene, polycaprolactone,polychlorotrifluoroethylene (PCTFE) perfluoropolyether (PEPE),polydimethylsiloxane (PDMS), polyepoxide, polyester (PEs),polyetheretherketone (PEEK), polyetherimide (PEI), polyetherimide,polyethersulfone (PES), polyethylenetetrafluoroethylene (ETFE),polyethyleneoxide, polyglycolic acid (PGA), polyglycolide,polyisobutene, polyisoprene, polyketone, polylactic acid (PLA), polyllyldiglycol carbonate monomer, polyrnethyl pentene (PMP),polymethylpentene, polyoxymethylene (POM), polyphenyl ether (PPE),polyphenylene vinylene, polyphenylene, polypropylene (PP),polypropylene, polystyrene (PS), polystyrene, polysulfide, polysulphone(PSU), polyurethane (PO), polyvinyl, polyvinyl carbazole, polyvinylfluoride (PVT), polyvinyl pyridine, polyvinylidene chloride (PVDC),polyvinylidene fluoride (PVDF), thermoplastics, thermosets, elastomers,pentacene, poly(3,4-ethylenedioxythiophene) (PEDOT),poly(styrenesulfonate) (PSS), poly(3-hexylthiophene) (P3HT),poly(3-octylthiophene) (P3OT), poly(C-61-butyric acid-methyl ester)(PCBM), poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene](MEH-PPV), Poly(vinyl acetate) (PVAc). Poly(Vinyl pyrrolidone) (PVP),Poly(NN-dimethylacrylamide) (PDMA), Poly(methylmethacrylate-comethacrylicacid) P(MMA-co-MAA), Trogamid,Nylon-Trogamid-T, Poly(aclylic acid) (PAA) and etc.

Furthermore, in the present invention, the organic material can co-existwith the inorganic material. For example, in a hybrid matelial, anorganic material could be mixed with an inorganic material at thenanometer level, so as to form a new molecular composite material. Insuch molecular composite material, the binding may be formed viaintermolecular forces, including van der Waals force, hydrogen bond,ionic bond and covalent bond. Accordingly, the property of the finalhybrid material could be the synergy of both inorganic properties andorganic properties, which helps to meet the specific requirements formany highly desired performances. Another example would be mixing theorganic material and the inorganic material homogeneously orheterogeneously. Another example would be employing a coupling agent, onan inorganic material in order to modify its surface characteristics.Another example would be forming a specific organic-inorganic mixture,such as inorganic particles capped by an organic material, or inorganicparticles embedded in an organic layer.

The co-presence of these two different materials render the buffer layera good adhering ability to both organic and inorganic materials, so asto ensure that the buffer layer 122 can fit with different film layermaterials. In the present invention, the buffer layer can be made ofboth organic material and inorganic material, as being described indetail above. In comparison to the buffer layer formed by a single typeof material, the buffer layer formed by such mixed materials can fitwith different requirements for the appearance of touch panel, via theselection of various materials with different indices of refraction.

In addition, with adjusting the index of refraction and thickness of thebuffer layer 122, it is possible to make its index of refraction matchthe indices of refraction of the layer on top of it and the layer belowit. In this way, it can improve the optical transmission properly of thetouch panel, so as to make the produced touch panel with a moredesirable appearance. For example, in the case a buffer layer 122 has anindex of refraction n₁, a film layer 121 has an index of refractionn_(f), and a sensing layer has an index of refraction n_(T), then n₁should be greater than n_(f), but is smaller than n_(T), i.e.n_(f)<n₁<n_(T): and preferably, it would be close to the value of thesquare root of the product of n_(f) and n_(T), i.e., n₁≈√{square rootover (n_(f)×n_(T))}. In this way, the optical properties, such as indexof refraction, of the three layers (sequentially, film layer, bufferlayer and sensing layer) arranged in order, either gradually increasingor gradually decreasing. As a result, light can travel smoothly throughthese three layers without a big sudden change, which makes the formedtouch panel looks more appealing.

Moreover, the buffer layer 122 is also capable of functioning as abuffer to reduce the mechanical stress generated between the film layerand the sensing layer located on two sides of the buffer layer. There isparticularly important in certain situations, such as significanttemperature increase or decrease, or peeling the glass plate off. Asdescribed previously, the film layer may be made of an organic material,such as polyimide (PI). On the other hand, the sensing layer is usuallymade of inorganic materials. In this regard, the PI film layer wouldhave a very high coefficient of thermal expansion (CTE); whereas thesensing layer may have a pretty low CTE. In addition, the mechanicalcharacteristics of the PI film layer and the sensing layer aredramatically different, too. Therefore, in the situations mentionedabove, a significant stress could be generated between the film layerand the sensing layer. Such a stress may not only negatively affect theappearance of touch panel, but also compromise the touch panel'sfunction. With the introduction of a buffer layer between the film layerand the sensing layer, via the buffer layer's buffering function, thepotential stress generated between the film layer and the sensing layerwould be effectively minimized. Therefore, the introduction of a bufferlayer between the film layer and the sensing layer can significantlyimprove the quality of the formed touch panel.

Based on the foregoing, the buffer layer should be formed by a materialwhose CTE value is between the film layer and the sensing layer, andmake sure that it is not close to one of them against the other. Forexample, if the PI film layer's CTE is about 1000, while the sensinglayer's CTE is a one digit value, then the desired CTE value of thebuffer layer would be a number of three digits and should not be tooclose to the sensing layer, i.e., not in the range approximately between1 to 100, nor be too close to the film layer end, i.e., not within therange greater than 900. So, preferably, the CTE value of the bufferlayer would be close to the midpoint, between the film layer and thesensing layer. If the difference between film layer's CTE and sensinglayer's CTE is 100%, then the CTE of the buffer layer in neither the 10%close to film layer's CTE nor the 10% close to the sensing layer's CTEis desirable. This is another reason why the buffer layer may be made ofpartial inorganic material and partial organic material, which helps toadjust the mechanical characteristic (such as CTE) of the buffer layer.

Further, the thickness of the buffer layer 122 is usually within therange of 10 angstrom (Å) to 3000 angstrom (Å). In addition, the bufferlayer 122 can be formed through the process of printing, coating orlithography. In the case when the buffer layer 122 is formed throughsuch a printing or coating approach, it has a reduced stress betweensubsequently formed sensing layer and film layer, so as to reduce thesensing layer deformation induced by such stress. In one embodiment, thebuffer layer 122 is formed by the following steps. A liquid includingmaterial described above is coated on the first film layer 121, cured byUV-light, and then baked. Finally, the solid buffer layer 122 is formedon the film layer 121.

The buffer layer 122 and the film layer 121 together have formed abearing layer 120 on top of the first plate 100. In comparison to thefilm layer 121, the buffer layer 122 has a relatively higher hardness.In this way, the bearing layer 120 formed by a buffer layer 122 that hasa higher hardness along with a film layer 121 that has a betterflexibility will have both good releasing ability and good bearingability, which would further improve the reliability of the componentssubsequently formed on the bearing layer 120. It needs to be noted thatin comparison to the buffer layer 122 formed by a single type ofmaterial (such as silicon dioxide), the buffer layer formed by theforegoing mixed materials has the advantages to adjust the stress of thebuffer layer 122, thus during the releasing process, it helps toincrease the stability of the entire touch panel structure. Although thebearing layer has better bearing ability than the film layer thecritical supporting effect to the respective layers during themanufacturing process of the touch panel is still provided by the firstplate or the second plate as mentioned above. In this way, the formedtouch panel is with a thinner and lighter structure and a lowerproduction cost. In another embodiment, the bearing layer 120 may be asingle layer and will have both good releasing ability and good bearingability, which would further improve the reliability of the componentssubsequently formed on the bearing layer 120.

As shown in FIG. 3, a sensing layer 130 is formed on top of the bufferlayer 122. The sensing layer 130 is located within the central area M ofthe first plate 100. As also shown in FIG. 15, which is a schematicstructural view of touch panel sensing layer of one embodiment of thepresent invention. The sensing layer 130 comprises multiple pieces offirst electrode block 131, which are disposed along a first direction;multiple lines of first wire 132 connect neighboring first electrodeblocks 131 along the first direction, multiple pieces of secondelectrode block 133, which are disposed along a second direction: themultiple pieces of second electrode block 133 are arranged on both sidesof the multiple lines of first wire 132; an insulating block 135 isformed on each of the multiple lines of first wire 132, and a secondwire 134 connecting two neighboring second electrode blocks 133 alongthe second direction is formed on each of the insulating block 135;i.e., the insulating block 135 is located between the first wire 132 andthe second wire 134, so as to ensure the insulation between the firstwire 132 and the second wire 134, wherein, the first direction isdifferent from the second direction, and preferably they areperpendicular to each other. It is noted that the structure of sensinglayer is not limited to the mode shown in FIG. 15, for example, thesensing, layer is single layer in which sensing electrode blocks areformed in comb-shape, cross-shape, or wave shape. In another embodiment,the sensing layer is single layer in which the at least one of firstsensing electrodes and second electrode have geocodes and are notoverlap with each other. In another embodiment, the sensing layer is amulti-layer stack in which the first sensing electrodes, the secondsensing electrodes, and insulator between two sensing electrodes arethree different and respective sublayers.

The process of sensing layer 130 formation comprises the steps set forthbelow, first, forming the first wire 132 on the buffer layer 122; next,forming the insulating block 135 on each of the first wire 132; andfinally forming the first electrode block 131, the second electrodeblock 133, as well as the second wire 134. Alternatively, in anotherembodiment of the present invention, first, forming the first electrodeblock 131, the second electrode block 133, as well as the first wire132; next, forming the insulating block 135 on each of the first wire132: and finally, forming the second wire 134 on the first wire 132.

In addition, the process of sensing layer 130 formation also comprisesthe steps of forming multiple signal lines 136; the first electrodeblocks 131 located along, the same axial direction (i.e., firstdirection) forming a serial sensing electrodes via electric, connectionsbetween the first wire 132, which would further electrically connectedto the corresponding signal line 136; the second electrode blocks 133located, along the same axial direction (i.e., second direction) forminga serial sensing electrodes via electric connections between the secondwire 134, which would further electrically connected to thecorresponding signal line 136. The sensing signal generated from thefirst electrode blocks 131 and the second electrode blocks 133 istransmitted via the signal line 136 to a controller (not shown in thefigures). The controller is able to calculate the location of thetouching based on the sensing signal. It needs to be noted that thequantity and arrangement of the signal line 136 can be adjustedaccording to various sensing layer 130 structures; and are thus notlimited to the mode shown in FIG. 15. More specifically, there are couldbe multiple convergence areas of the signal lines 136, and the signallines 136 that connects the same serial sensing electrodes can adopt amode of bilateral lead.

The first electrode block 131 and the second electrode blocks 133 aremade of transparent conductive material, such as transparent conductiveoxide, which may include indium tin oxide (ITO), aluminum doped zincoxide (AZO), zinc oxide, antimony tin oxide (ATO), tin dioxide, indiumoxide, or a combination of the foregoing. The first electrode block 131and the second electrode blocks 1.33 may also be made of nano-silver,nano-carbon tube, metal mesh or other conductive material. The firstwire 132, the second wire 134, as well as the signal line 136 canutilize the same transparent conductive material as that of theaforementioned electrode blocks; they may also utilize non-transparentconductive materials, such as metal and alloy, comprising gold, silver,copper, molybdenum, aluminum or a combination of the foregoing. Thefirst electrode block 131, second electrode blocks 133, first wire 132and second wire 134 can be formed via the processes of sputtering andlithography, or other method such as screen printing, spraying and etc.

It should be noted, concerning the touch panel of the present invention,in one preferred embodiment, the first electrode block 131, secondelectrode blocks 133, the first wire 132 and the second wire 134 are allindium tin oxide formed by the process of sputtering at low temperature,wherein the low temperature is about 20 to 80° C. In comparison to thesputtering at high temperature, the overall stress of the indium tinoxide formed via the process of sputtering at low temperature isrelatively low, which makes it suitable for the subsequent step of firstplate removal, as well as improves the stability of the touch sensingstack formed on top of the bearing layer 120.

More specifically, the first wire 132 is formed via sputtering andlithography at low temperature. At this stage, the formed first wire 132is non-crystalline indium tin oxide; then performing baking to the firstwire 132, so as to transform the non-crystalline indium tin oxide into acrystalline indium tin oxide; next, forming each insulating block 135 onthe first wire 132; and then at low temperature, forming the firstelectrode block 131, second electrode blocks 133 and the second wire 134via sputtering and lithography. Similarly, at this stage, the formedfirst electrode block 131, second electrode blocks 133 and the secondwire 134 are all non-crystalline indium tin oxide; and finally, bakingthe first electrode block 131, second electrode blocks 133 and thesecond wire 134, so as to convert the non-crystalline indium tin oxideinto crystalline indium tin oxide. The baking processing mentioned aboveis usually performed at a temperature equal to or greater than 180° C.and equal to or less than 350° C. and preferably greater than or equalto 220° C. and equal to or less than 240° C.

The step of baking the first wire 132 can avoid the formed first wire132 being corroded by the etchant used in the formation of the firstelectrode block 131, second electrode blocks 133 and the second wire134. In addition, it can increase light transmission, reduce impedanceand improve electrical conductivity of the first wire 132. Similarly,the baking process to the first electrode block 131, second electrodeblocks 133 and second wire 134 can increase light transmission, reduceimpedance and improve electrical conductivity of the first electrodeblock 131, second electrode blocks 133 and the second wire 134.

In another embodiment of the present invention, the first electrodeblock 131, second electrode blocks 133 and first wire 132 are formed viasputtering and lithography at low temperature, at this stage, the formedfirst electrode block 131, second electrode blocks 133 and first wire132 are all non-crystalline indium tin oxide; then performing baking tothe first electrode block 131, second electrode blocks 133 and firstwire 132, so as to transform the non-crystalline indium tin oxide into acrystalline indium tin oxide; next, forming each insulating block 135 onthe first wire 132; and then forming the second wire 134, at this stage,the second wire 134 is non-crystalline indium tin oxide; and finally,baking the newly formed second wire 134, so as to transform thenon-crystalline indium tin oxide into a crystalline indium tin oxide.The indium tin oxide disclosed in this embodiment is just an example fordescription, and should not limit the scope of the present invention.

Next, in reference to FIG. 4, a second plate 150 is formed on thesensing layer 130. In addition, the second plate 150 is able topartially or even entirely cover the buffer layer 122. Via the secondadhering layer 140, the second plate 150 is adhered to the sensing layer130 and the buffer layer 122. The materials that can be used to make thesecond plate 150 include polyethylene terephthalate (PET) polymer or anyother material that is able to support a film layer component andfacilitate its transfer to a cover, including glass, cyclic olefincopolymer (COP, Arton), polypropylene (PP), and etc. The second adheringlayer 140 can be a removable adhesive, and the second adhering layer 140may comprise a non water soluble adhesive or any suitable material thatis able to adhere two layers together and subsequently to be dissolvedor removed via appropriate approaches. In one embodiment, the secondplate 150 and the second adhering layer 140 can be integrated as asingle-sided adhesive tape. The second adhering layer 140 has onesurface facing the second plate 150 and one opposite surface facing thesensing layer 130. The adhesiveness of one surface of the secondadhering layer 140 which faces the sensing layer 130 could be reduced ordiminished by illumination, UV irradiation, heat, cold or thecombination thereof, and meanwhile, under the same treatment, anothersurface of the second adhering layer 140 which faces the second plate150 remains unchanged. Accordingly, during the step of removing thesecond plate, the second adhering layer 140 can be removed along withthe second plate 150.

In references to FIGS. 5A, 5B and 6, the first plate 100 is removed fromthe film layer 121. As shown in FIGS. 5A and 5B, which is an explodedview of 5A, along the inner side of the first adhering layer 110, thefirst adhering layer 110 and the structure on top of the first adheringlayer 110 (i.e., a part of the film layer 121, the buffer layer 122, thesecond adhering layer 140 and the second plate 150 corresponding theperipheral region N of the first plate) can be removed, i,e., cuttingalong the CC′line as shown in FIG. 5A. Next, the first plate 100 isremoved from the film layer 121. Since the first adhering layer 110 thatmaintains the major adhering function has been removed prior to theremoval of the first plate 100, it can reduce influence of the stressfrom the removal of the first plate 100 on the film layer 121 and thestructures formed on the film layer 121. In addition, during theremoving of the first adhering layer 110, the cutting parameters can becontrolled, so as to ensure that the first plate 100 will not bedamaged. In this way, the first plate 100 becomes reusable, which wouldhelp to reduce the production costs.

In one embodiment of the present invention, besides the first adheringlayer 110 and the structure on top of the first adhering layer 110, thefirst plate 100's portion that is below the first adhering layer 110 isremoved, along the inner side of the first adhering layer 110, i.e.,along the CC′ line as shown in FIG. 5A. Next the partially cut firstplate 100 that corresponds to the central region M of the first plate100 is removed from the film layer 121. Alternatively, in anotherembodiment, between the step of sensing layer 130 formation and the stepof second plate 150 formation, along the inner side of the firstadhering layer 110, cutting off the first adhering layer 110 and thestructure on top of the first adhering layer 110; and at the same time,the first plate 100 is retained, and the first plate 100 will be removedafter the formation of the second plate 150.

It needs to be noted, during removing the first plate 100, othermeasures could be taken to facilitate the releasing process, such asremoving the first plate 100 from the film layer 121 via the measures ofsolution soaking heating, cooling, peeling by force or a combinationthereof. In this regard, the solution can be water, alcohol, propyleneglycol monomethyl ether acetate (PGMEA) solution, N-Methyl-2-pyrrolidone(NMP) and etc; with utilization of the heating or cooling treatment, thefirst plate 100 is heated or cooled, since the thermal expansioncoefficient of the bearing layer 120 and that of the first plate 100 aredifferent, a stress is generated, which will further facilitate thereleasing.

Next, in reference to FIG. 7, a cover 170 is attached to the film layer121. The cover 170 and the film layer 121 can be made attached to eachother tightly through stacking pressure from the binding layer 160 orother measures. Also, as the film layer 121 is located between the cover170 and buffer layer 122, i.e., the layer stacking order would be, fromtop to bottom, cover 170, binding layer 160, film layer 121, bufferlayer 122, sensing, layer 130, second adhering layer 140 and secondplate 150. The cover 170 is able to protect the structures below it. Itcan be made of glass, polyimide (PI), polypropylene (PP), polystyrene(PS) acrylonitrile-butadiene-sryrene (ABS), polyethylene terephthalate(PET), polyvinyl chloride (PVC), polycarbonate (PC), polyethylene (PE),polymethyl methacrylate (PMMA), polytetrafluoro ethylene (PTFE) or othertransparent materials. In order to increase the strength of the cover170, the six sinfaces of the cover 170 may all be chemical strengthened,or two opposite surfaces of the cover 170 may be chemical strengthenedand four lateral surfaces may be physically strengthened. The cover 170could be formed by cutting the glass substrate into small pieces firstwhich matches the size of one touch panel module and then chemicallystrengthening above pieces. Compared with the conventional method whichthe glass substrate is chemically strengthened first and then cut intosmall pieces, the cover 170 of the present embodiment of the claimedinvention has improved edge strength and bulk strength. In addition, thecover 170 can be made of either hard material or flexible material.Moreover, the cover 170 may comprise two flat surfaces, two curvedsurfaces or one flat surface and one curved surface, such as 2.5D shapeor 3D shape. Since the film layer component. (i.e., the bearing layer120 combined with the sensing layer 130) of the present invention isthinner and more flexible than conventional touch assembly including oneglass and one film or two films or two glasses as supporting substrates,the film layer component could be attached to the hard cover withvarious curvature or even a flexible cover and perform touching functionwell, which will further increase the freedom of touch panel design. Theupper surface of the cover 170, namely the side that is opposing theside attached to the film layer 121, can be used as a touching surfaceof the touch panel. Furthermore, the binding layer 160 could be made ofsolid or liquid transparent optical glue or other suitable transparentbonding materials.

Moreover, on either side of the cover 170, a shield layer 180 may beprovided and attached to the cover 170. The shield layer 180 is locatedon at least one side of the cover 170, so as to shield the signal line(136 shown in FIG. 15). In this way, the signal line will not been seenby a user from the upper surface of the cover 170. In one embodiment ofthe present invention, the shield layer 180 is located below the cover170, i.e., it is located between the lower surface of the cover 170 andthe film layer 121. In another embodiment, the shield layer 180 islocated on the upper surface of cover 170, i.e., it is located on theside of the cover 170 opposing to the film layer 121.

Alternatively, the shield layer 180 can be a decoration film(Deco-film). Specifically, the Deco-film may include a transparent filmand the shield mask, and the shielding mask is located around theperipheral area of the transparent film. The Deco-film can be eitherdisposed on the upper surface of the cover, or used to replace the cover170 and the shield layer 180. The material of the shield layer 180 canbe color ink, color photoresist, or a combination of the two. Further,the shield layer 180 can be in either a single layer structure or amultiple layer structure. For example, the single layer structure may bea black ink layer. The multiple layer structure may be a stack of inklayer and photo resist layer, a stack of white ink layer and black inklayer, or a stack of white ink layer, black ink layer and photo resistlayer.

Finally, in reference to FIG. 8, the second plate 150 and the secondadhering layer 140 are removed from the sensing layer 130. Morespecifically, the second adhering layer 140 is pre-treated, includingoptical treatment, heating, cooling treatments, or a combinationthereof. For example, according to the various types of the materialsfor the second adhering, layer 140, respective treatments of UVirradiation, heating or cooling can be utilized to reduce the adhesionof second adhering layer 140. And then, the second plate 150 and thesecond adhering layer 140 are easily removed from the sensing layer 130.The particular removing method can be determined according to thematerial of second adhering layer 140. The present invention is notlimited on this issue. Noteworthily, during the process of transferringthe film layer 121 with the buffer layer 122 and the sensing layer 130from the second plate 150 to the cover 170, preferably the second plate150 is made of flexible material, and the cover 170 is made of rigidmaterial, such as strengthened glass. By attaching flexible material tothe rigid material, the yield rate of the transferring step will beimproved, the thickness of the binding layer 160 will be reduced, andgas bubbles generated in the binding layer will be avoided.

A touch panel 10 as shown in FIG. 8 is finally formed via the stepsmentioned previously. The touch panel 10 comprises the stackingstructure from top to bottom, the cover 170, the binding layer 160, thefilm layer 121, the buffer layer 122 and the sensing layer 130, namely,the film layer 121 is next to the cover 170; the buffer layer 122 isnext to the film layer 121; the sensing layer 130 is next to the bufferlayer 122; the binding layer 160 is located between the cover 170 andthe film layer 121. Further, the touch panel 10 may also comprises ashield layer 180. The shield layer 180 is located on at least one sideof the cover 170. The structure, material and production method of theforegoing have already been disclosed previously. So, they will not berepeated hereinafter. The generated touch panel 10 can be applied intocomputer system, mobile phone, digital media player, ultrabooks wearabledevices, in-vehicle computers and many other display devices with touchpanel.

It is noted that following the completion of the steps as illustrated inFIGS. 1 to 8, a flexible circuit board with a controller can be furtherattached to the signal line 136 of the sensing layer 130 located on theconnection position with an anisotropic conductive adhesive. Incomparison to the approach of directly attaching the flexible circuitboard after the step shown in FIG. 3, the present invention firstlycompletes the steps shown in FIGS. 1 to 8, and then attaches theflexible circuit board. It is easily understood that in such a way, itcan avoid the issue that during the process of removing the first plate100 or the second plate 150, the flexible circuit board might accidentlyfall off Therefore, it is helpful to improve the overall stability ofthe touch panel.

In reference to FIGS. 9 and 10, it has shown another embodiment of theforming method of the touch panel of the present invention. It is notedthat, the step shown in FIG. 9 follows the step shown in FIG. 3. Thesteps prior to the step shown in FIG. 9 are identical to the steps shownin FIGS. 1-3. So, they will not be repeated herein. As shown in FIG. 9,post the formation of the sensing layer 130, the procedure furthercomprises the step of forming a protection layer 200 on the sensinglayer 130. The protection layer 200 has protective effect to the sensinglayer 130. It is able to reduce the negative effect on the sensing layer130 from the removals of the second adhering layer 140 and the secondplate 150. In addition, it can also reduce the damage to the sensinglayer 130 from the air, water (vapor) or other corrosive substances inthe environment. Moreover, the protection layer 200 needs to expose theconnection position where the signal line connecting the flexiblecircuit board, which facilitates to connect to an external controller.

The protection layer 200 may be made of at least one of organicmaterials, inorganic materials, composite materials or polymermaterials. Specifically, they include thermosetting resin, silica,photoresist, and other suitable transparent insulating materials. In onepreferred embodiment of the present invention, the protection layer 200may adopt a mixed material similar to that of the previous mentionedbuffer layer 122, i.e., an organic material and an inorganic material.In another embodiment, the protection layer comprising, titanium dioxide(TiO₂), silicon dioxide (SiO₂), zirconium dioxide (ZrO₂) and thecombination thereof, or a compound formed by titanium dioxide (TiO₂),silicon dioxide (SiO₂) and organic material(s). With adjustment of therefractive index and thickness of the protection layer 200, and incombination with the introduction of the buffer layer 122, it helps toimprove the problem of undesired touch panel appearance, which is causedby the light reflection difference between the areas with electrodeblock and the areas without electrode block. For example, the surface ofthe protection layer 200 which is apart from the sensing layer 130 maybe adhered to a display device so as allow the touch panel 10 to becombined with the display device. The protection layer 200 comprises arefraction index n₂, and preferably n₂ is within the range set by theupper and lower layers of the protection layer 200. In one embodiment,the protection layer 200 is located between the sensing layer 130 and anadhering layer which is used for attaching to the display device. Insuch a case, the refraction index n₂ of the protection layer 200 wouldbe less than the refraction index n_(T) of the sensing layer 130 butgreater than the refraction index n_(A) of the adhering layer; i,e.,n_(A)<n₂<n_(T) and preferably, it would be close to the value of thesquare root of the product of n₃ and n_(T)i.e., n₂≈√{square root over(n_(A)×n_(T))}. In one preferred embodiment of the present invention,the thickness of the protection layer 200 can be 0.01 μn to 0.3 μm.

The protection layer 200 can be formed by the printing approach viaconvex plate or roller. The protection layer 200 formed in this way canhelp to reduce the stress between the subsequently formed sensing layer130 and other layers, so as to improve the stability of the protectionlayer 200. And at the same time, it allows a conveniently removing ofthe second plate and the second adhering layer, and reduces stress. Inone embodiment, the protection layer 200 is formed by coating, curing byUV light, and re-curing by heat. In other preferred embodiment of thepresent invention, based on the needs of the respective application,other approaches, such as sputter, chemical vapor deposition (CND),inkjet printing, slit coating, spin coating, spray coating or rollercoating, can also be utilized to form the protection layer 200.

In reference to FIGS. 4-8, and steps following the step shown in FIG. 9are similar to the steps shown in FIGS. 4-8; except that the secondplate 150 and the second adhering layer 140 are formed on top of theprotection layer 200. The first plate 100 and the first adhering layer110 are firstly removed; and then the cover 170 is attached to the workpiece; next, the second plate 150 and the second adhering layer 140 areremoved, so as to form the touch panel 20, which further comprises theprotection layer 200. As shown in FIG. 10, the touch panel 20 comprises,from top to bottom stacked the cover 170, the binding layer 160, filmlayer 121, buffer layer 122, sensing layer 130, and the protection layer200. Concerning the structure, material and manufacturing method of theforegoing components, they have already been described previously, andthus will not be repeated herein.

The protection layer 200 can be either a single layer structure or amultiple layer structure. In one embodiment, referring to FIG. 11, theprotection layer 200 is a multi layer structure and includes a firstprotection layer 201 and a second protection layer 202. The firstprotection layer is between the sensing layer 130 and the secondprotection layer 202. The surface of the second protection layer 202which is apart from the first protection layer 201 may be attached to adisplay device so as allow the touch panel 10 to be combined with thedisplay device. The formation of the first and second protection layeris identical as that of the protection layer as disclosed above. So, itwill not be repeated herein.

The first protection layer 201 and the second protection layer 202 maybe made of different material and perform different function. The firstprotection layer 201 may be made of at least one of organic materials,inorganic materials, composite materials or polymer materials. In onepreferred embodiment of the present invention, the first protectionlayer 201 may adopt a mixed. material similar to that of the previousmentioned buffer layer 122, i.e., an organic material and an inorganicmaterial. In another embodiment, the protection layer comprisingtitanium dioxide (TiO₂), silicon dioxide (SiO₂), zirconium dioxide(ZrO₂) and the combination thereof, or a compound formed by titaniumdioxide (TiO₂), silicon dioxide (S_(i)O₂) and organic material(s). Inaddition, the second protection layer 202 may include thermosettingresin, silica, photoresist, and other suitable transparent insulatingmaterials. With adjustment of the refractive index and thickness of thefirst protection layer 201, and in combination with the introduction ofthe buffer layer 122, it helps to improve the problem of undesired touchpanel appearance. which is caused by the light reflection differencebetween the areas with electrode block and the areas without electrodeblock. For example, the first protection layer 201 comprises arefraction index n₂, and preferably n₂ is within the range set by theupper and lower layers of the first protection layer 201. In oneembodiment, the first protection layer 201 is located between thesensing layer 130 and the second protection layer 202. In such a case,the refraction index n₂ of the first protection layer 201 would be lessthan the refraction index n_(T) of the sensing layer 130 but greaterthan the refraction index n₃ of the second protection layer, i.e.,n₃<n₂<n_(T); and preferably, it would be close to the value of thesquare root of the product of n₃ and n_(T), i.e., n₂≈√{square root over(n₃×n_(T))}. In one preferred embodiment of the present invention, thethickness of the first protection layer 201 can be 0.01 μm to 0.3 μm.

The first protection layer 201 helps to improve the problem of undesiredtouch panel appearance, which is caused by the light reflectiondifference between the areas with electrode block and the areas withoutelectrode block. In addition, the second protection layer 202 provides aprotective effect to the sensing electrode and reduces the damage to thesensing layer 130 from the air, water (vapor) or other corrosivesubstances in the environment. The second protection layer 202 mayinclude thermosetting resin, silica, photoresist, and other suitabletransparent insulating materials.

In the foregoing embodiments, the formation of one touch panel is takenfor example. In order to improve the production efficiency and reducecost, the formation of multiple touch panels will be disclosed in thisparagraph, In FIGS. 12A, 12B to 14, it has shown the manufacturingprocess of the touch panel of another embodiment of the presentinvention. It may simultaneously form a plurality of film components 30(including film layer, buffer layer, sensing layer, second adheringlayer, second plate) on the first plate, prior to the step of attachingthe film components 30 and the cover, the multiple film components 30have been separated. In this way, it can improve the productionefficiency and reduce costs. As shown in FIGS. 12A and 12B, which is anexploded view of FIG. 12A. a plurality of region V can be pre-arrangedon a big, piece of first plate 300, the area of the region V isdetermined by touch panel's size. Next, on the first plate 300, it hassequentially formed film layer 121, buffer layer 122; and then, on topof the formed buffer layer in the plurality of regions V, simultaneouslyforming a plurality of corresponding sensing layer 130, then attaching asecond plate 150 to the sensing layer by a second adhering layer 140(alternatively, similar to the procedure shown in FIG. 9, prior to theformation of the second plate, a protection layer can be formed on topof the sensing layer).

It is noted that in such a case, the plurality of sensing layers areisolated from each other, while all other components, including firstplate, film layer, buffer layer, sensing layer, second adhering layerand second plate, are all in a respective one big piece form.Subsequently, the first plate 300 is removed, and then a third plate 310is attached to the film component. Similar to the structure of thesecond adhering layer and second plate, the third plate 310 may be asingle-sided adhesive tape including a flexible film and an adhesivelayer, which the film component is attached to. The third plate 310 hasa protective and supporting effect to the film component and reducesdamage in the following separation step. The film components in one bigpiece form (including film layer, buffer layer, sensing layer, secondadhering layer and second plate) is separated into multiple small piecesof film components by knife, laser, or any other cutting tool. As inFIG. 13, it has shown one example that the film components are separatedinto a few groups, and with each group containing three film components30. And it is readily understood that the film component with larger orsmaller size containing more or fewer film components in each group canbe separated, too. Next, the third plate 310 is removed, then aplurality of covers will be attached to the small pieces of filmcomponent, and finally remove the second plate, as well as separate themultiple region V based on the corresponding sensing layers, as shown inFIG. 14. In this way, a plurality of touch panels connecting together isseparated into multiple isolated individual touch panels (20 in FIG.10).

It is also noted that during the process of adopting a large piece offirst plate 300 to simultaneously form multiple touch panels as shown inFIGS. 12A, the first adhering layer for connecting the film layer to thefirst plate 300 can be arranged at the peripheral area of first plate300, for example, along the four edges of first plate 300. In anotherembodiment, the first adhering layer can also be arranged at theperipheral area of each of the regions V, in order to further enhancethe attachment of the film layer to the first plate 300. In such a way,during the process when the first plate 300 being removed, the adheringlayer around the first plate 300 and around each region V will besimultaneously removed. Alternatively, the first adhering layer may beprovided only around each region V, and there is no first adhering layerexisting around the first plate 300. Yet, the present invention is notlimited by such configurations.

The present invention has provided a touch panel and the manufacturingmethod thereof. Via the supporting effect from the first plate a sensinglayer is formed on top of the film layer. Next, by virtue of thetransferring effect of the second plate, the film layer and the sensinglayer formed on it are attached to a cover. In such a way, the formedtouch panel becomes lighter, thinner and of lower production costs.Moreover, as the sensing layer is located on the other side from theside where the film layer attaches the cover, it helps to avoid theissue that the connecting of sensing layer and flexible circuit boardmay affect the flatness of the attachment between the film layer and thecover. Furthermore, a buffer layer is formed between the film layer andthe sensing layer, which helps to minimize the damage to the film layerduring the formation process of the sensing layer, and further reducethe adverse effect on the film layer and sensing layer from the stressgenerated during the process of removing the first plate.

The foregoing is just a few preferred embodiments of the presentinvention. They are not to limit the present invention. Themodifications, alternations and substitutions within the spirit andprinciple of the present invention should be in the scope claimed in thepresent invention.

What is claimed is:
 1. A touch panel, comprising a film layer; a bufferlayer; a sensing layer having a refraction index n_(T); a cover attachedto the film layer through a binding layer; wherein the upper surface ofthe cover which is opposing the bottom surface attached to the filmlayer is a touch surface of the touch panel; said binding layer beingbetween said cover and said film layer; said film layer being betweensaid binding layer and said buffer layer; said buffer layer beingbetween said film layer and said sensing layer; said buffer layercomprising an inorganic material and an organic material; a protectionlayer having a refraction index n₂; an adhering layer having arefraction index n_(A); said protection layer attaching to said sensinglayer and comprising an inorganic material and an organic material; andsaid protection layer is located between said sensing layer and saidadhering layer; wherein said refraction index n_(A)<said refractionindex n₂<said refraction index n_(T).
 2. The touch panel as set forth inclaim 1, comprising said film layer being formed with polyimide (PI). 3.The touch panel as set forth in claim 1, comprising said film layerbeing formed with a material selected from the group consisting ofpolypropylene (PP), polystyrene (PS), acrylonitrile-butadiene-styrene(ABS), polyethylene terephthalate (PET), polyvinyl chloride (PVC),polycarbonate (PC), polyethylene (PE), polymethyl methacrylate (PMMA),polytetrafluoro ethylene (PTFE), cyclic olefin copolymer (COP) or acombination thereof.
 4. The touch panel as set forth in claim 1,comprising said film layer having a thickness of 0.1 μm to 15 μm.
 5. Thetouch panel as set forth in claim 1, comprising said film layer having athickness of 2 μm to 5 μm.
 6. The touch panel as set forth in claim 1,comprising said inorganic material comprising titanium oxide and siliconoxide.
 7. The touch panel as set forth in claim 1, comprising saidinorganic material comprising zirconium oxide.
 8. The touch panel as setforth in claim 1, comprising said buffer layer having a thickness of 10angstrom (Å) to 3000 angstrom (Å).
 9. The touch panel as set forth inclaim 1, comprising an index of refraction of said buffer layer isbetween an index of refraction of said film layer and said refractionindex n_(T) of said sensing layer.
 10. The touch panel as set forth inclaim 1, comprising a coefficient of thermal expansion (CTE) of saidbuffer layer is between a coefficient of thermal expansion of said filmlayer and a coefficient of thermal expansion of said sensing layer. 11.The touch panel as set forth in claim 1, comprising said protectionlayer being formed with a material selected from the group consisting ofzirconium oxide, a compound formed by titanium oxide and an organicmaterial, a compound formed by silicon oxide and an organic material, acompound formed by zirconium oxide and an organic material and acombination thereof.
 12. The touch panel as set forth in claim 1, saidsensing layer comprising a plurality of first electrode block; saidplurality of first electrode block being disposed in a first direction;a plurality of first wire; said plurality of first wire connectingneighboring first electrode blocks; a plurality of second electrodeblock; said plurality of second electrode block being disposed in asecond direction; a plurality of second wire; said plurality of secondwire connecting neighboring second electrode blocks; said plurality ofsecond electrode block being arranged on both sides of said plurality offirst wire; a plurality of insulator being arranged between saidplurality of first wire and said plurality of second wire; saidplurality of first wire being insulated from said plurality of secondwire; a plurality of signal line; said plurality of signal lineelectrically connecting said plurality of first electrode block and saidplurality of second electrode block; and said plurality of firstelectrode block being insulated from said plurality of second electrodeblock.
 13. The touch panel as set forth in claim 12, further comprisinga shield layer; said shield layer being disposed on at least one side ofsaid cover; and said shield layer shielding said plurality of signalline.
 14. The touch panel as set forth in claim 1, wherein:n₂≈√n_(A)×√n_(T).
 15. A touch panel, comprising a film layer; a bufferlayer; a sensing layer having a refraction index n_(T); a cover attachedto the film layer through a binding layer; wherein the upper surface ofthe cover which is opposing the bottom surface attached to the filmlayer is a touch surface of the touch panel; said binding layer beingbetween said cover and said film layer; said film layer being betweensaid binding layer and said buffer layer; said buffer layer beingbetween said film layer and said sensing layer; a coefficient of thermalexpansion (CTE) of said buffer layer being between a coefficient ofthermal expansion of said film layer and a coefficient of thermalexpansion of said sensing layer; a protection layer having a refractionindex n₂; an adhering layer having a refraction index n_(A); saidprotection layer attaching to said sensing layer and comprising aninorganic material and an organic material; and said protection layer islocated between said sensing layer and said adhering layer; wherein saidrefraction index n_(A)<said refraction index n₂<said refraction indexn_(T).
 16. The touch panel as set forth in claim 15, comprising saidfilm layer being formed with polyimide (PI).
 17. The touch panel as setforth in claim 15, comprising said film layer being formed with amaterial selected from the group consisting of polypropylene (PP),polystyrene (PS), acrylonitrile-butadiene-styrene (ABS), polyethyleneterephthalate (PET), polyvinyl chloride (PVC), polycarbonate (PC),polyethylene (PE), polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE), cyclic olefin copolymer (COP) or a combination thereof.18. The touch panel as set forth in claim 15, comprising said film layerhaving a thickness of 0.1 μm to 15 μm.
 19. The touch panel as set forthin claim 15, comprising said film layer having a thickness of 2 μm to 5μm.
 20. The touch panel as set forth in claim 15, comprising said bufferlayer comprising an inorganic material and an organic material.
 21. Thetouch panel as set forth in claim 20, comprising said inorganic materialcomprising titanium oxide and silicon oxide.
 22. The touch panel as setforth in claim 15, comprising: said inorganic material comprisingzirconium oxide.
 23. The touch panel as set forth in claim 15,comprising said buffer having a thickness of 10 angstrom (Å) to 3000angstrom (Å).
 24. The touch panel as set forth in claim 15, comprisingan index of refraction of said buffer layer is between an index ofrefraction of said film layer and said refraction index n_(T) of saidsensing layer.
 25. The touch panel as set forth in claim 15, comprisingsaid protection layer being formed with a material selected from thegroup consisting of zirconium oxide, a compound formed by titanium oxideand an organic material, a compound formed by zirconium oxide and anorganic material, and a combination thereof.
 26. The touch panel as setforth in claim 15, said sensing layer comprising a plurality of firstelectrode block; said plurality of first electrode block being disposedin a first direction; a plurality of first wire; said plurality of firstwire connecting neighboring first electrode blocks; a plurality ofsecond electrode block; said plurality of second electrode block beingdisposed in a second direction; a plurality of second wire; saidplurality of second wire connecting neighboring second electrode blocks;said plurality of second electrode block being arranged on both sides ofsaid plurality of first wire; a plurality of insulator being arrangedbetween said plurality of first wire and said plurality of second wire;said plurality of first wire being insulated from said plurality ofsecond wire; a plurality of signal line; said plurality of signal lineelectrically connecting said plurality of first electrode block and saidplurality of second electrode block; and said plurality of firstelectrode block being insulated from said plurality of second electrodeblock.
 27. The touch panel as set forth in claim 26, further comprisinga shield layer; said shield layer being disposed on at least one side ofsaid cover; and said shield layer shielding said plurality of signalline.
 28. The touch panel as set forth in claim 15, wherein:n₂≈√n_(A)×√n_(T).